class_docstr: This context manager makes a wrapper of input_tensor
  When created, the input_tensor is dilated,
  the input_tensor resumes to original space when exiting the context.
code: def __enter__(self):
      if self.dilation_factor > 1:
          self._tensor = tf.space_to_batch_nd(
              self._tensor,
              self.block_shape,
              self.zero_paddings,
              name="dilated",
          )
      return self
  
file_path: NiftyNet/niftynet/layer/dilatedcontext.py
imports: from __future__ import absolute_import, print_function
  import tensorflow
  from niftynet.layer import layer_util
label_desc: Use image node_id 2 for calling the DilatedTensor obj's underlying member method code with example usage: obj.__enter__() and returns: self